What Is CRISPR Gene Editing?

  • By Ari Daniel
  • Posted 08.11.17
  • NOVA

Scientists have a new tool to edit genes in human cells to repair mutations. What is it?

Running Time: 01:24


Onscreen: Human gene editing is here, and scientists have a new tool that makes it easy.

It's called CRISPR—a mini sharpshooting assassin.

CRISPR is made of two parts: A piece of RNA that acts as a guidance system and an enzyme.

Inside a cell nucleus, CRISPR's guidance system hunts for a specific DNA sequence, like a problematic gene.

When CRISPR finds its target (a section of DNA that matches the guide RNA), CRISPR clamps onto that DNA and slices it.

When the cell tries to repair the damage, it uses an engineered, healthy part of the gene to fix it. 

This editing tool isn't perfect yet. But it is powerful. So now is the time to ask—when and how should it be used?



Digital Producer
Ari Daniel
Editorial Review
Julia Cort & Tim De Chant
Special Thanks
C. Dustin Rubinstein
Director, Genome Editing and Animal Models Facility
University of Wisconsin Madison
© WGBH Educational Foundation 2017


The McGovern Institute for Brain Research at MIT


(main image: CRISPR and DNA)
The McGovern Institute for Brain Research at MIT

Related Links

  • No More Mosquitoes?

    A new technology could make diseases like Zika a thing of the past. But should we use it?

  • Personal Genome Project

    Learn why George Church of Harvard Medical School hopes to recruit 100,000 people and sequence all of their DNA.

  • Cracking Your Genetic Code

    We are on the brink of a new era of personalized, gene-based medicine. Are we ready for it?

  • Personal DNA Testing

    Genetic testing for risk of future illness is now open to anyone. But is it a good idea?